The present invention relates to an airbag apparatus for an automobile, a folding method of an airbag, and a folding apparatus of an airbag.
An airbag used for an airbag apparatus for a passenger-side airbag apparatus of an automobile is described in Japanese Patent Publication No. 2709024, Japanese Patent Publication No. 2652751, Japanese Patent Application Laid-open No. H4-100754 and the like. A folding apparatus of an airbag is described in Japanese Patent Application Laid-open No. H6-48261 and Japanese Utility Model Application Laid-open No. H6-55896.
An airbag Is required to smoothly and swiftly expand and develop to effectively moderate an impact of a collision applied to an occupant, and to reduce the pressure applied to the occupant from the airbag itself.
A folding apparatus of an airbag Is required to smoothly fold an airbag at high speed, and to fold the airbag such that excellent developing performance can be secured.
It is an object of the present invention to provide an airbag apparatus for an automobile, a folding method of an airbag, and a folding apparatus of an airbag which satisfy the above-mentioned requirements.
To achieve the above object, a first mode of an airbag apparatus of the present invention includes a bag-like airbag and a case body. The airbag is developed by flowing-in of gas. The case body includes an airbag accommodation portion and a projection port. The airbag is folded and accommodated in the airbag accommodation portion. The folded airbag develops by pressing is developed through the projection port. The folded airbag includes a first developing portion and an aggregate. The first developing portion includes one end connected to the case body. The aggregate comprises second developing portions extending from the other end of the first developing portion. The second developing portions of the aggregate are gathered toward the other end of the first developing portion.
With the above arrangement, when gas is supplied into the airbag folded and accommodated in the airbag accommodation portion of the case body, the gas is first introduced into the first developing portion. By the flowing-in of the gas, the first developing portion is developed and the aggregate projects from the projection port by a predetermined amount. Subsequently, the gas is introduced into each of the second developing portions constituting the aggregate through the first developing portion, and each of the second developing portions is developed. The plurality of second developing portions are provided in the aggregate and when each of the second developing portions is developed, the aggregate projects outside the case body. Therefore. the aggregate is developed smoothly substantially in the entire circumferential direction substantially around a predetermined point. For this reason, when the aggregate is developed, the developing speeds of various portions of the airbag is uniformed, and airbag is restrained from being partially developed at high speed.
The first developing portion may be wound around an outer periphery of the aggregate.
With the above arrangement, when the gas is introduced into the folded airbag, the first developing portion projects from the protection port while being rewound. Therefore, it is possible to allow the airbag to incline and project from the projection port, and for example, it is possible to allow the aggregate to project in a direction away from an object to be protected.
A second mode of the airbag apparatus of the invention includes a bag-like airbag and a case body. The airbag is developed by flowing-in of gas. The case body includes an airbag accommodation portion and a projection port. The airbag is folded and accommodated in the airbag accommodation portion. The folded airbag develops by passing through the projection port. The airbag is developed in two stages. The airbag in a first stage projects to a prescribed point away from the projection port. The airbag in a second stage is developed around the prescribed point.
With the above arrangement, at the time of development, the airbag can be smoothly developed substantially around the prescribed point away from the projection port in a state in which the airbag projects from the projection port by a predetermined amount.
In a first mode of a folding method of an airbag of the invention, the airbag is first folded into a shape including a first developing portion and second developing portions. The first developing portion is provided at its one end with an opening. Each of the second developing portions extends from the other end of the first developing portion. Next, the second developing portions are gathered toward the other end of the first developing portion to form an aggregate.
A second mode of the folding method of the airbag of the invention comprises the following four steps. In a first step, the airbag is held such that the opening is directed downward. In a second step, the inside of the airbag is pressurized to expand the airbag upward in substantially vertical direction. In a third step, the airbag is folded into a substantially T-shape including a first and two second developing portions. The first and second developing portions are formed by pushing the expanded airbag from the outside and folding portions thereof inward. The first developing portion has a flat-plate shape extending in substantially vertical direction from an opening of one end of the first developing portion. Each of the second developing portions has a flat-plate shape extending substantially horizontal direction from the other end of the first developing portion. Each of the first and second developing portions is folded into a width capable of being accommodated in an airbag accommodation portion. In a fourth step, the second developing portions are folded and superposed on the other end of the first developing portion, thereby forming an aggregate.
The first developing portion may be wound around an outer periphery of the aggregate.
Each of the first and second developing portions may be folded into a width which can be accommodated in the airbag accommodation portion, and the aggregate may be formed by folding the second developing portion and superposing the folded second developing portions on the other end of the first developing portion. With this arrangement, the aggregate can be formed easily, and the producing cost of the airbag is reduced. In this case, the aggregate can be formed easier by forming the first and second developing portions into the plate-like shape.
Each of the second developing portions may be folded into the corrugate shape. With this arrangement, the developing characteristics of the airbag can be enhanced.
The length of the second developing portions may be different from the length of the first developing portion. With this arrangement, a desired developed shape of the airbag can be obtained.
Each of the second developing portions may have an upward developing portion to be developed upward and a downward developing portion to be developed downward. When the second developing portions are developed, the downwardly developing portions may project greater than the upward developing portions.
When the airbag apparatus is disposed in the instrument panel of an automobile, a lower space of the airbag apparatus (space between the airbag apparatus and the passenger) is greater than an upper space of the airbag apparatus (space between the airbag apparatus and the front glass). According to the above folding method, the airbag can be smoothly developed such as to excellently fill both the upper and lower spaces.
A first mode of the airbag folding apparatus of the invention includes first and second corrugating units. The first and second corrugating units are respectively disposed on one and the other surfaces of the airbag folded into a flat-plate shape, and are opposed to each other. The first and second corrugating units respectively includes first and second folding bodies, first and second link means and first and second driving means. Each of the first folding bodies includes a first abutment portion, and each of the second folding bodies includes a second abutment portion. Each of the link means connects the corresponding folding bodies to each other. Each of the driving means drives at least one of the corresponding folding bodies and the link means The first abutment portions are arranged at a predetermined distance, and advance and retreat with respect to the one surface of the airbag by the first driving means. The second abutment portions are arranged at a predetermined distance and advance and retreat with respect to the other surface of the airbag by the second driving means. When both the first and second abutment portions advance, the first abutment portion comes in contact with and pushes the one surface of the airbag, and the second abutment portion comes in contact with and pushes the other surface of the airbag. With this operation, one of the abutment portions is inserted between the other abutment portions, and the airbag is bent into the corrugate shape between the first and second abutment portions.
With the above arrangement, when the abutment portions of the plurality of folding bodies of the first and second corrugating units disposed on both surfaces of the airbag such as to oppose to each other approach each other, the abutment portion of each of the corrugating units advances toward the airbag, and the airbag is folded into the corrugate shape. In this folding process, each of the abutment portion is moved while the predetermined point of the airbag is held, the sliding contact between the abutment portion and the airbag is restrained and thus, a force is restrained from being applied, and the speedup of the folding operation is possible. Since the folding bodies are connected to each other by the link means, the folding bodies are associatively moved with respect to each other, and the driving means can be omitted. Therefore, the structure of the apparatus can be simplified, and the producing cost of the apparatus can be reduced.
At least one of the first and second link means may be formed into a pantagraph shape.
A second mode of the airbag folding apparatus of the invention includes first developing portion holding means, second developing portion folding means and aggregate folding means. The first developing portion folding means folds a portion of the airbag which is continuous with the opening and forms the first developing portion. The first developing portion is provided at its one end with the opening. The second developing portion folding means folds a portion of the airbag which is continuous with the first developing portion and forms a plurality of flat plate like second developing portions. Each of the second developing portions extends from the other end of the first developing portion. The aggregate folding means fold the second developing portions and superpose the latter on the other end of the first developing portion, thereby forming the aggregate.
The aggregate folding means may have the first and second corrugating units of the first mode.
The second mode of the folding apparatus may further have airbag holding means, and a mounting member may be mounted to the opening of the airbag. The airbag holding means holds the mounting member in a state in which the opening is directed downward, pressurizes the inside of the airbag to expand the latter upward in substantially vertical direction, thereby stabilizing the airbag in position. The first developing portion folding means may have a first developing portion restriction plate. The first developing portion restriction plate pushes the expanded bag from the outside and folds the latter inward, thereby forming the first developing portion having a substantially vertical plate shape. The second developing portion folding means may have a second developing portion restriction plate. The second developing portion restriction plate pushes the expanded airbag from the outside and folds the latter inward, thereby forming the second developing portion having the substantially horizontal flat plate shape.
With the above arrangement, it is possible to mechanize the folding operation of the airbag having excellent developing characteristics that when the gas flows in, the first developing portion first develops and then, the second developing portions develop and, the producing cost is reduced. Further, since the inside of the airbag is pressurized and expanded in a state in which the opening to which the mounting member is mounted is directed downward, and the airbag is stabilized in position, the operation of attaching and detaching the airbag is improved.